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ePaper created 2014-05-07, 13:23:14 | version 1.30.01
117 Dr. Iris Trick Phone +49 711 970-4217 iris.trick@igb.fraunhofer.de Dr. Anke Burger-Kentischer Phone +49 711 970-4023 anke.burger-kentischer@ igb.fraunhofer.de Funding We would like to thank the Fraunhofer-Gesellschaft for funding the project “TOXIKOMB” within the scope of its SME-oriented internal research program (MEF). Project partners We would like to thank our colleagues at the Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg for such good co- operation. IAF. Fig. 2 illustrates the change in the impedance as a re- sponse by the cells to nickel acetate which was used as one of the test substances. Supplementary IR measurement technology and integration in a measuring cell The method is supplemented by measurements using infrared spectroscopy (IR) which on the one hand permits the detec- tion of chemical substances. On the other hand IR highlights chemical effects on proteins, amino acids and nucleic acids. The IR source used in the process is a quantum cascade laser (QCL) developed at the IAF. Measurements using infrared spectroscopy provide the proof of concept that cell compo- nents such as the protein structure of mammalian and bacte- rial cell systems change in a substance-specific way (Figs. 3 and 4). It is intended that both measuring methods ultimately be inte- grated into a measuring cell suitable for inline monitoring. Outlook This subject matter is primarily relevant for drinking water suppliers but also for large residential complexes or industrial enterprises who wish to continuously monitor their facilities. In this way consumers will be offered a greater level of safety. 1 Microbial growth on a diamond electrode. 2 Electrochemical measurements on tap water with Caulobacter crescentus as a biosensor on diamond. When nickel acetate is added, a clear increase in the test signal is shown (below). Above: Control, no change in impedance. 3 Acrylamide reacts with nucleic acids and proteins of human cells, detectable from a change in infrared bands. 4 Response of Escherichia coli to acrylamide, reaction with amino acids detectable. 3 4 ATRunits wavenumber cm–1 0.06 0.04 0.02 0.00 –0.02 –0.04 1800 1600 1400 1200 1000 800 human cells: control human cells: acrylamide α-helix and β-sheet nucleic acids ѵsPO2 – ѵasPO2 – amideII amideI ATRunits wavenumber cm–1 0.06 0.04 0.02 0.00 –0.02 –0.04 1800 1600 1400 1200 1000 E. coli: control E. coli: acrylamide α-helix and β-sheet CH2 (side chains of amino acids) amideII amideI Contacts